The invention concerns a composite sleeve comprising elements attached together, designed for the creation of a sealing joint for the connection of ducts used for gravitational sanitary drainage. More specifically, it concerns a sleeve for the impermeable assembly of uniform ends of pipes whose outer surfaces are in the rough, non-machined state, these pipes being made of a fiber-cement, cast iron, or any other suitable material.
The composite sleeve and the sealing joint incorporating it are designed to ensure imperviousness to pressures which may range up to approximately 2 bars, while incorporating wide outer diametral tolerances of the uniform ends of the assembled pipes. The sleeve and the joint also allow angular deviation of one pipe in relation to the other.
Patent No. FR 1 439 234 discloses an angularly-deviated composite pipe assembly incorporating diametral tolerances of the two uniform ends of the pipes. In this composite sleeve, a collar comprising thin, flexible, elastic end lips is enclosed in a rigid binding ring whose ends are folded inwardly at right angles, i.e., toward the axis. This assembly is impervious to the internal pressure of the liquid in the duct, which tends to press the thin lips on the pipes, but not to the external pressure of a liquid capable of lifting and pushing each lip away from the smooth end on which it is elastically pressed.
Patent FR 2 444 864 also discloses a composite sleeve for the impervious connection of two fiber-cement pipes, which allows wide outer diametral tolerances and angular deviations of the pipes and provides imperviousness to both external and internal pressure. The composite sleeve is produced by welding two sealing gaskets to the ends of a rigid tubular element or connection sleeve. Welding requires the use of specified materials, in this instance a polyolefin used for the tubular element or sleeve, and EPDM rubber for the sealing gaskets, because of their suitability for welding. The sealing gaskets comprise a single lip incorporating an end flange containing, in its core, an elastic band which tightens over the smooth ends of the pipes.